1. Field of the Invention
Embodiments of the invention relate generally to an LC quadrature oscillator, and more particularly, to a phase and amplitude mismatch compensator that compensates for phase and amplitude mismatches between I/Q clock signals generated by the LC quadrature oscillator.
2. Description of the Related Art
In general, an LC quadrature oscillator includes two LC oscillators that are cross-coupled with each other to generate I/Q clock signals. During operation of the LC quadrature oscillator, there are LC mismatches (e.g., inductance and/or capacitance mismatches) between the two LC oscillators such the I/Q clock signals generated in the LC quadrature oscillator have phase and amplitude mismatches. These phase and amplitude mismatches between the I/Q clock signals generated in the LC quadrature oscillator can degrade the system performance when the LC quadrature oscillator is used in a clock and data recovery (CDR) circuit or an image reject receiver that requires exact I/Q clock signals for signal processing. For example, the phase and amplitude mismatches between the I/Q clock signals can increase a bit-error rate (BER) of a CDR circuit and reduce an image rejection ratio (IRR) of an image reject receiver. Therefore, there is a need for an accurate phase and amplitude mismatch compensator for an LC quadrature oscillator.